"Reduce initial server response time" issue with IPv6
I have using the "GCV 9999 MO EPYC" machine to host a website. Sever is really super fast. I am using Apache+Nginx (reverse proxy)+MariaDB+PHP7.4 on Debian11.5.
I found a weird issue. Whenever I enable IPv6 on Nginx, I get "Reduce initial server response time" on the Google pagespeed test (~2.5s). If I disable IPv6, I do not get any error.
BunnyDNS is my DNS hosting provider.
Any idea what could be the problem?